1. Field of the Invention
This invention relates to a method for imparting a fatigue and wear-resistant protective coating on a metal surface.
2. Description of the Prior Art
Metal objects such as gears, bearing components, splines, cams, cutting tools, knives, razor blades, pumps, compressors and the like, when in use in relative motion with other surfaces, are subject to contact, to wear and to cyclic stressing leading to fatigue, impairing their useful lives. Prior to the present invention, as described in commonly assigned U.S. Pat. 3,329,742, dinonylphenyl hydrogen phosphonate has been added to lubricating oils as an antioxidant and extreme pressure additive. It has been found when lubricating oil compositions containing dinonylphenyl phosphonate are used, wear rate is reduced and fatigue life is increased; these improvements have been attributed to the presence of reaction films formed with the metal surfaces under dynamic conditions of service.